Method and apparatus for fabrication of structures used in construction of tower base supports

ABSTRACT

Disclosed are apparatus and corresponding methodologies for providing a base support, such as including concrete, and used such as for a wind-driven generator. Precast concrete cylinders are stacked in place upon a platform that may be partially precast and partially cast in place during assembly and supported, in certain embodiments, by plural concrete legs, the other ends of which are supported on a unitary or subdivided concrete foundation. In other embodiments, the platform may be supported by ribbed concrete panels. The concrete cylinders are glued together using an epoxy and then secured by an internal vertical post tension system extending from the platform to the upper most cylinder. Methodologies and apparatus for fabrication of concrete structure used in constructing the base support are also disclosed, with a focus on staves and various ring piece constructions.

PRIORITY CLAIM

This application claims the benefit of previously filed U.S. Provisionalpatent application entitled “CONCRETE BASE SUPPORT FOR WIND-DRIVEN POWERGENERATORS,” assigned U.S. Ser. No. 61/061,173, filed Jun. 13, 2008; andclaims the benefit of previously filed U.S. Provisional patentapplication entitled “BASE SUPPORT FOR WIND-DRIVEN POWER GENERATORS,”assigned U.S. Ser. No. 61/113,354, filed Nov. 11, 2008; and claims thebenefit of previously filed U.S. Provisional patent application entitled“BASE SUPPORT FOR WIND-DRIVEN POWER GENERATORS,” assigned U.S. Ser. No.61/143,460, filed Jan. 9, 2009; and claims the benefit of previouslyfiled U.S. Provisional patent application entitled “BASE SUPPORT FORWIND-DRIVEN POWER GENERATORS,” assigned U.S. Ser. No. 61/171,965, filedApr. 23, 2009; and claims the benefit of previously filed U.S.Provisional patent application entitled “METHOD AND APPARATUS FORFABRICATION OF STRUCTURES USED IN CONSTRUCTION OF TOWER BASE SUPPORTS,”assigned 61/174,700, filed May 1, 2009; all of which are fullyincorporated herein by reference for all purposes.

FIELD OF THE INVENTION

The present subject matter relates to towers. More specifically, thepresent subject matter relates to methodology and apparatus forfabrication of staves and other components as may be used in towerconstructions, such as may be used in conjunction with dynamicstructures such as wind-driven power generators or windmills or withother structures such as water towers.

BACKGROUND OF THE INVENTION

Construction of towers for support of various items has been practicedfor many years. Various towers of various materials have been providedto support electrical transmission lines including wooden, steel, and,more recently, concrete. In like manner, wind driven apparatus includingwindmills and wind-driven power generators in various forms and designedfor many purposes, including pumping of water from wells as well as,more recently, generation of electrical power, have also been developed.

U.S. Pat. No. 3,793,794 to Archer et al. entitled “Stacked Column” isdirected to a column comprised of a plurality of concrete-filled stackedtubes.

U.S. Pat. No. 4,406,094 to Hempel et al. entitled “Apparatus forAnchoring Self-supporting, Tall Structures” is directed to an anchoringself-supporting tall structure such as masts, towers, or the like in afoundation. The mast or tower may be used to support a wind-driven powergenerator.

U.S. Pat. No. 5,761,875 to Oliphant et al. entitled “Reinforced concretePole with Attachment Mechanism” is directed to an attachment mechanismwhich provides a structurally sound means to attach a reinforcedconcrete pole to a support structure.

U.S. Pat. No. 6,532,700 to Maliszewski et al. entitled “Flange With CutFor Wind Tower” is directed to a flange for making a tower for a windgenerator made up of a plurality of cylindrical steel segments.

U.S. Pat. No. 7,155,875 to Henderson entitled “Method of Forming aPerimeter Weighted Foundation For Wind Turbines And The Like” isdirected to a weighted foundation having a central pier pedestal and anenlarged base space outwardly and extending below the pedestal.

U.S. Pat. No. 5,586,417 to Henderson, et al. entitled “Tensionless pierfoundation” is directed to a hollow, cylindrical pier foundation isconstructed of cementitious material poured in situ between inner andouter cylindrical corrugated metal pipe shells.

The disclosures of all the patents referenced herein are incorporated byreference, for all purposes.

In an article entitled “Precast concrete elements for wind powerindustry,” German company Enercon GmbH has described methodology forcasting concrete. Mexican company Postensa Wind Structures describes onits website www.postensaws.com a tilt up, precast on-site constructionsystem for concrete towers for use with wind driven power generators.

While various implementations of tower constructions have beendeveloped, and while various combinations of materials have beenemployed for tower construction, no design has emerged that generallyencompasses all of the desired characteristics as hereafter presented inaccordance with the subject technology.

SUMMARY OF THE INVENTION

In view of the recognized features encountered in the prior art andaddressed by the present subject matter, improved apparatus andmethodology are presently disclosed for providing base supports forwindmills and wind-driven power generators (e.g., wind turbines). Itshould be appreciated that while the present disclosure is directed inexemplary fashion to support structure involving precast concrete,various presently disclosed constructions may be alternatively practicedin accordance with the present subject matter.

In addition, it should be appreciated that while the present disclosureis directed in exemplary fashion to support structure for windmills andsimilar devices, such is not necessarily a specific limitation of thepresent subject matter. For example, it should be clear to those ofordinary skill in the art that a tower constructed in accordance withthe present technology may well be used to support, for example, atelevision transmitter aerial or other radio signal broadcasting aerial.Alternatively, towers constructed in accordance with present technologymay be used to support any type device that may require placement abovelocal ground level for more effective operation. Such other present usesmay include, for example, such as electrical power transmission linesand athletic field lighting equipment.

In one exemplary configuration, support for windmills may be provided bystacking on-site a plurality of precast concrete cylinders to form aself-supporting tower.

In one of its simpler forms, a first number of the precast concretecylinders may be provided as reinforced prestressed concrete while asecond number of the precast concrete cylinders may be provided as ultrahigh performance fiber reinforced concrete.

In accordance with aspects of certain embodiments of the present subjectmatter, methodologies are provided to secure individual precast concretecylinders together using adhesives.

In accordance with certain aspects of other embodiments of the presentsubject matter, methodologies have been developed to provide a temporarysupport for a raised platform.

In accordance with yet additional aspects of further embodiments of thepresent subject matter, apparatus and accompanying methodologies havebeen developed to provide an internal vertical post tensioning systemwithin the stacked concrete cylinders to maintain structural integrityof the stacked assembly.

In accordance with yet further embodiments of the present subjectmatter, a ribbed concrete block structure may be provided as analternative support for a raised tower supporting platform.

In yet still further alternative embodiments of the present subjectmatter, a tower supporting platform may correspond in part to a precastportion and a field poured portion.

In accordance with further embodiments of the present subject matter, apoured-in-place concrete circular strip footing may be providedrequiring little or no excavation.

In accordance with aspects of certain exemplary embodiments, a conicalskirt may be provided to distribute the tower load to the foundation.

In accordance with yet further aspects of certain exemplary embodimentsof the present subject matter the foundation could be precast and castmonolithically with vertical stave elements.

In accordance with yet still further aspects of certain exemplaryembodiments, the foundation may be configured to add additional deadload by means of external ballasts.

In accordance with yet still further aspects of certain exemplaryembodiments, improved methodology and apparatus for fabricating concretestructures used in the formation of base supports are provided.

One present exemplary method in accordance with the present technologyrelates to a method for fabricating precast concrete structures for usein the construction of a support tower, Such a method may includeproviding a concrete form having a transverse axis and a longitudinalaxis, such concrete form defining a casting cavity having at least oneinjection port and at least one ventilation port; tilting such concreteform about such transverse axis or such longitudinal axis or both suchthat a first area of such casting cavity is relatively raised withrespect to a second area of such casting cavity; and injecting concreteinto such casting cavity through such at least one injection port.

In variations of the foregoing exemplary method, such injecting step maycomprise injecting concrete into such casting cavity upwardly from thesecond area of such casting cavity to the relatively raised first areathereof. Also, optionally, such tilting step may include selectivelytilting such concrete form about both its transverse axis and itslongitudinal axis. In some instances, such tilting step may includetilting such concrete form about 45° about its transverse axis and about6° about its longitudinal axis.

In other alternatives of the foregoing, such method may further includeproviding such concrete form with a plurality of anchors; and securingpre-stressing tendons to such plurality of anchors prior to injectingconcrete into such casting cavity. In another alternative, such methodmay include in instances vibrating such concrete form to assistinjection and/or consolidation of concrete into such casting cavity; andcuring such concrete in such casting cavity to form a casting. Suchexemplary method may also include optionally curing such concrete insuch casting cavity to form a casting; and heating such concrete priorto injecting and/or heating such casting cavity to assist curing of suchconcrete in such casting cavity.

Other variations of such exemplary method may include providing suchinjection port with a shut-off valve; and closing such shut-off valveafter concrete has been injected into such injection port. Yet otherpresent exemplary variations may relate to providing such concrete formwith a plurality of injection ports disposed along such casting cavity;injecting concrete made with high flow or self-consolidating concretemix into a first injection port of such plurality of injection ports;and injecting concrete made with high flow or self-consolidatingconcrete mix into a second injection port of such plurality of injectionports, with such second injection port relatively raised with respect tosuch first injection port.

In some instances, such casting cavity may be shaped to form one of aconcrete stave with a top portion and with a lower portion having agreater width than such top portion, or to form a concrete tubularstructure.

Another present exemplary methodology embodiment relates to a method offabricating structures for use in construction of a support tower. Suchan exemplary present method may include providing respective outerdiameter and inner diameter forms with the outer diameter form situatedover the inner diameter form so as to collectively provide a concreteform defining a casting volume, such concrete form having at least oneinlet for injection of concrete into such casting volume and at leastone outlet for the displacement of air therefrom; injecting concreteinto such casting volume; curing such concrete in such casting volume soas to form a casting; generating a first thermal gradient between suchcasting and such outer diameter form; removing such outer diameter formfrom such casting; generating a second thermal gradient between suchcasting and such inner diameter form; and removing such casting fromsuch inner diameter form.

In the foregoing exemplary method, optionally generating such firstthermal gradient may include spraying steam onto such outer diameterform, or using at least one heater embedded in such outer diameter form,or combinations thereof. Similarly, generating such second thermalgradient may include spraying water or air or combinations thereof atambient temperature onto such inner diameter form. Such step of removingsuch outer diameter form may include lifting such outer diameter form.Such step of removing such casting from such inner diameter form mayinclude pushing up on such casting, or lifting such casting orcombinations thereof.

Yet another present exemplary embodiment relates to a method offabricating concrete structures for use in the construction of a supporttower, such a method preferably comprising providing a lower concreteform defining a transverse axis and a longitudinal axis; providing anupper concrete form having a top surface and a bottom surface; invertingsuch upper concrete form so that such bottom surface of such upperconcrete form is above such top surface of such concrete form; placingstructural members onto such bottom surface of such upper concrete form;securing such upper concrete form to such lower concrete form so as tocollectively construct a concrete form assembly defining an enclosedcasting cavity having at least one concrete injection port and at leastone ventilation port; tilting such concrete form assembly about suchtransverse axis or such longitudinal axis or both such that a firstcasting area of such casting cavity is raised with respect to a secondcasting area of such casting cavity; injecting concrete into suchcasting cavity through such at least one concrete injection portthereof, upwardly from such second casting area of such casting cavityto such first casting area thereof such casting cavity; curing suchconcrete in such enclosed casting cavity to form a casting; separatingsuch upper concrete form from such lower concrete form; and removingsuch casting.

In one exemplary variation of the foregoing, such tilting step mayinclude tilting such concrete form about 45° about such transverse axisand about 6° about such longitudinal axis. In another present exemplaryvariation, such method may further include providing such concrete formwith a plurality of injection ports disposed along such casting cavity;injecting concrete into a first injection port of such plurality ofinjection ports; and injecting concrete into a second injection port ofsuch plurality of injection ports, with such second injection portrelatively raised with respect to such first injection port. In stillfurther variations, such casting cavity may be shaped to form one of aconcrete stave with a top portion and with a lower portion having agreater width than such top portion, or to form a concrete tubularstructure.

It is to be understood by those of ordinary skill in the art from thedisclosure herewith that the present subject matter equally relates toboth methodology as well as apparatus subject matter. For example, onepresent exemplary embodiment relates to a concrete form, preferablycomprising a lower concrete form; and an upper concrete form secured tosuch lower form to define an enclosed casting volume within suchconcrete form. In such exemplary apparatus, preferably such lower andupper concrete forms collectively further define in such casting volumeat least one concrete injection port and at least one ventilation port,and provide such casting volume with a shape for forming therein aconcrete stave with a top portion and with a lower portion having agreater width than such top portion.

In variations of the foregoing apparatus, such exemplary concrete formmay further include anchors for securing pre-stressing tendons. Stillfurther, in some variations, such ventilation port may be configured tobe closed off; and such injection port may include a shut-off valve. Inyet other alternatives, such concrete form may further include aplurality of injection ports disposed along such casting volume; anembedded heater; and a vibrator. In some embodiments, such upper formand such lower form each may include structural reinforcing members toallow such concrete form to be transported by a crane or cart. In some,such concrete form may further include at least one attachment mechanismfor securing such concrete form to a crane or cart.

In another present exemplary embodiment, an exemplary concrete form maycomprise an inner diameter form; and an outer diameter form receivedover such inner diameter form to define a casting volume within suchconcrete form. In such arrangement, preferably per present subjectmatter such inner and outer diameter forms collectively may furtherdefine in such casting volume at least one injection port and at leastone ventilation port, and provide such casting volume with a shape forforming therein a concrete tubular structure.

In some present variations of the foregoing, such concrete form mayfurther include anchors for securing post-tensioning ducts.Alternatively, such ventilation port may be configured to be closed off;and such injection port may include a shut-off valve. In othervariations, such concrete form may further include a plurality ofinjection ports disposed along such casting volume; an embedded heater;and a vibrator. Also, such outer diameter form and such inner form mayeach include structural reinforcing members to allow such concrete formto be transported by a crane or cart. Such concrete form may furtherinclude at least one attachment mechanism for securing such concreteform to a crane or cart; and such inner diameter form may comprise atleast one jacking port.

Additional objects and advantages of the present subject matter are setforth in, or will be apparent to, those of ordinary skill in the artfrom the detailed description herein. Also, it should be furtherappreciated that modifications and variations to the specificallyillustrated, referred and discussed features, elements, and steps hereofmay be practiced in various embodiments and uses of the present subjectmatter without departing from the spirit and scope of the subjectmatter. Variations may include, but are not limited to, substitution ofequivalent means, features, or steps for those illustrated, referenced,or discussed, and the functional, operational, or positional reversal ofvarious parts, features, steps, or the like.

Still further, it is to be understood that different embodiments, aswell as different presently preferred embodiments, of the presentsubject matter may include various combinations or configurations ofpresently disclosed features, steps, or elements, or their equivalents(including combinations of features, parts, or steps or configurationsthereof not expressly shown in the figures or stated in the detaileddescription of such figures).

Additional embodiments of the present subject matter, not necessarilyexpressed in the summarized section, may include and incorporate variouscombinations of aspects of features, components, or steps referenced inthe summarized objects above, and/or other features, components, orsteps as otherwise discussed in this application. Those of ordinaryskill in the art will better appreciate the features and aspects of suchembodiments, and others, upon review of the remainder of thespecification.

BRIEF DESCRIPTION OF THE DRAWINGS

A full and enabling disclosure of the present subject matter, includingthe best mode thereof, directed to one of ordinary skill in the art, isset forth in the specification, which makes reference to the appendedfigures, in which:

FIG. 1 illustrates an exemplary embodiment of a concrete base support,such as for a windmill, in accordance with the present technology, fullyinstalled and supporting a representative exemplary windmill;

FIG. 2 illustrates a portion of a lower section of the concrete basesupport in accordance with a exemplary embodiment of present subjectmatter, illustrating a temporary support tower, guy wires, and circularconcrete base support;

FIG. 3 is an enlarge perspective view of the top portion of thetemporary tower illustrated in FIG. 2 with a precast concrete transitionpiece placed thereon;

FIG. 4 illustrates the placement of a first pair of staves positioned inbalanced relationship on opposite sides of the transition piece;

FIG. 5 is a top view taken from line 16-16 of FIG. 4 showing a completedskirted base structure;

FIG. 6 illustrates a top perspective view of the precast transitionpiece with all stays in place and banded around with a corrugated metalcollar;

FIG. 7 illustrates a view similar to that of FIG. 6 but including asealing plate that forms a portion of a tower hydraulic liftingmechanism;

FIG. 8 illustrates a view similar to that of FIG. 7 but including atower lifting plate;

FIG. 9 illustrates a view similar to that of FIG. 8 and includingillustration of a first precast concrete tower section shown partiallyin phantom to better illustrate aspects of the internal construction;

FIG. 10 illustrates coupling of ducts within the staves and precastconcrete tower section to provide passageways for securing strands;

FIG. 11 illustrates sealing and circumferential clamping of the jointbetween the first section of precast concrete tower portion and theprecast transition piece;

FIG. 12 illustrates, partially in phantom, the stacking of additionalprecast concrete tower sections and the insertion into the stackedconcrete sections of a steel tower section;

FIG. 13 illustrates an exemplary tower in accordance with presenttechnology in a fully extended position and supporting a wind generator;

FIG. 14 illustrates a completed tower construction supporting a windgenerator but omitting the normally accompanying turbine blade assembly;

FIG. 15 is a cross section of a portion of a precast base includingballast fill and stave anchoring features in accordance with certainexemplary embodiments of the present technology;

FIG. 16 illustrates a cross section of an alternate configuration of theprecast base structure that is identical to that of FIG. 15 except thatthe upstanding wall section has been replaced with a separatedcorrugated metal structure in accordance with certain other exemplaryembodiments of the present technology;

FIG. 17 illustrates preliminary construction of a multi-stage tower basefor use with larger capacity turbines and higher towers;

FIG. 18 illustrates an exemplary implementation of “U” shaped tendons toprovide multiple joint crossing and enhanced stave retention;

FIG. 19 illustrates a top plan view of an exemplary concrete form usedto cast staves for use in exemplary embodiments of the presenttechnology;

FIG. 20 illustrates a cross-sectional view of an exemplary concrete formused to cast staves for use in exemplary embodiments of the presenttechnology, taken along section line 20-20′ as shown in present FIG. 19,with dotted line representation of the concrete form being tiltable inaccordance with present subject matter about a longitudinal axis of theform;

FIG. 21 illustrates a side view of an exemplary concrete form used tocast staves for use in exemplary embodiments of the present technology,with representative tilting of the concrete form relative to itslongitudinal axis, in accordance with certain aspects of the presentsubject matter;

FIG. 22 illustrates a side view of an exemplary concrete form used tocast staves for use in exemplary embodiments of the present technology,with such form illustrated while situated substantially parallel withthe floor;

FIG. 23 illustrates a side view of an exemplary concrete form used tocast staves for use in exemplary embodiments of the present technology,and illustrating such concrete form being lifted in the air by aplurality of attachment mechanisms, all in accordance with certainaspects of the present subject matter;

FIG. 24 illustrates a composite location key for subfigures, FIGS. 24Athrough 24D, which collectively illustrate an exemplary layout of afacility where concrete staves may be cast according to exemplarymethodology and apparatus of the present technology;

FIG. 25 illustrates a further exemplary concrete form in accordance withthe present subject matter, used to cast ring structures for use inexemplary embodiments of the present technology;

FIG. 26 illustrates another view of an exemplary concrete form used tocast ring structures for use in exemplary embodiments of the presenttechnology; and

FIGS. 27A through 27C variously illustrate the bottom surface of anexemplary inner diameter concrete form used to cast ring structures foruse in exemplary embodiments of the present technology, specificallywith FIGS. 27B and 27C illustrating, respectively, enlarged plan andcross-section views of exemplary jacking port features of the presenttechnology otherwise representatively illustrated in present FIG. 27A.

Repeat use of reference characters throughout the present specificationand appended drawings is intended to represent same or analogousfeatures, elements, or steps of the present subject matter.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

As discussed in the Summary of the Invention section, the presentsubject matter is particularly concerned with apparatus andcorresponding methodology for providing base supports, such as comprisedat least in part of precast concrete, and such as for windmills andwind-driven power generators, or other apparatuses.

Selected combinations of aspects of the disclosed technology correspondto a plurality of different embodiments of the present subject matter.It should be noted that each of the exemplary embodiments presented anddiscussed herein should not insinuate limitations of the present subjectmatter. Features or steps illustrated or described as part of oneembodiment may be used in combination with aspects of another embodimentto yield yet further embodiments. Additionally, certain features may beinterchanged with similar devices or features not expressly mentionedwhich perform the same or similar function.

Reference will now be made in detail to the presently preferredembodiments of the subject concrete base support, shown for example, insupport of representative exemplary windmills. With reference to thedrawings, FIG. 1 illustrates an exemplary embodiment of a concrete basesupport generally 100, such as for a windmill, in accordance with thepresent technology, illustrated as fully installed and supporting arepresentative generator generally 120 and accompanying turbine bladeassembly generally 122. Those of ordinary skill in the art willappreciate that particular internal details regarding such generator 120and turbine blade assembly 122 form no particular aspects of the presentsubject matter, wherefore further additional detailed discussion of suchdevices is not required for a complete understanding of the presentsubject matter.

Concrete base support 100 corresponds to a number or plurality ofsections, all of which are made of concrete in various forms, so as toprovide particular capabilities as required for desired support ofgenerator 120 and turbine blade assembly 122.

As may be seen from FIG. 1, concrete base support 100 corresponds to aleg section comprising, in an exemplary configuration, such as eightlegs representatively illustrated by leg 114. Various numbers of legsmay be practiced in accordance with the present subject matter. Each ofsuch legs 114 rests on an individual foundation block generally 116.Further, each such leg generally 114 is preferably inserted into one ofa corresponding number of mating holes 117 in a platform 112. In anexemplary configuration, platform 112 may be constructed of reinforcedconcrete, may be circular in shape, may have a diameter of twenty sixfeet and may be four feet thick. Each leg 114 may measure four feet byfour feet and have eight inch thick walls.

Portions 102, 104, 106, and 108 of concrete base support 100 preferablyvary in size as illustrated in and represented by FIG. 1, and alsopreferably are constructed with varying concrete compositions. Portion102 of concrete base support 100 corresponds to a number of stackedreinforced prestressed concrete cylinders representatively illustratedas cylinders 132, 134, 146. Each cylinder 132, 134, 136 may also includereinforcing bars (rebars), for example, common steel bar, as is commonlyused in reinforced concrete. Further, it should be noted that while thepresent description may speak of concrete cylinders, such descriptiondoes not necessarily mean that the outer and/or inner shape is circular.In fact the concrete cylinders constructed in accordance with thepresent technology may correspond to cylindrical, octagonal, hexagonal,or any other outside and/or inside surface formation or combinationsthereof.

Each of the concrete cylinders 132, 134, 136 in section 102 of concretebase support generally 100 preferably is substantially the same size andsimilarly constructed of reinforced prestressed concrete. Each of suchcylinders also is preferably constructed for mating assembly such thatthe top of one cylinder is shaped to mate with the bottom of the next,i.e., adjacent, cylinder. As the cylinders 132, 134, 136 are stacked,each preferably is adhesively secured together using, for example, anepoxy or grout. In an exemplary configuration, twenty cylinders may bestacked together to form section 102 of concrete base support 100 whereeach cylinder 132, 134, 136 may be six feet tall thereby producing asection 102 which is one hundred twenty feet tall.

Following assembly of section 102 of concrete base support 100, atransition ring or cylinder 104 is placed on the top cylinder of portion102. As may be seen from the representations of present FIG. 1, suchtransition cylinder 104 preferably varies in diameter from a diametercorresponding to the diameter of section 102 to a smaller diametermatching the diameter of the cylinders forming section 106. In anexemplary configuration, transition cylinder 104 may have a midpointdiameter of thirteen feet and have an eighteen inch thick wall.Transition cylinder 104 as well as each of the cylinders in portion 106of concrete base support 100 representatively illustrated as cylinders142, 144, 146 are formed of ultra high performance fiber reinforcedconcrete. In an exemplary configuration, the ultra high performancefiber reinforced concrete may employ steel fiber as the fiber componentof the concrete. In other embodiments, other fibers comprise of othermaterials, now known or later developed, may be utilized.

As previously referenced, each cylinder of section 106, representativelyillustrated as cylinders 142, 144, 146, of concrete base supportgenerally 100 is constructed from ultra high performance fiberreinforced concrete and may employ steel fiber for reinforcement. In anexemplary configuration, seven cylinders each fifteen feet tall may bestacked to produce a section 106 which is one hundred five feet tall.

Following assembly of section 106 of concrete base support 100, anadditional cylinder 108 preferably is affixed to the top most cylinderof portion 106. Top most cylinder 108 has a bottom portion configured tomate with the top cylinder of portion 106 and a top surface thatprovides a mounting surface for representative generator 120. Inaddition, there is provided an anchoring ring to secure one end of apost tensioning cable assembly that extends per the present subjectmatter from such anchoring ring to a corresponding anchor at platform112.

Once each of the various cylinders have been stacked and respectivelyglued into place, a cable 110 is passed through the hollow center ofeach of the stacked cylinders, secured at the anchor ring at the top ofthe string and at the anchor associated with platform 112 (i.e., at thebottom of the string) and tightened, thereby providing an internalvertical post tensioning system to assist in securing each of therespective cylinders.

With reference now to FIGS. 2-19, an exemplary embodiment of the presentbase support for wind-driven power generators will be described. As maybe seen in FIG. 2, a concrete base support and temporary towerconstruction may be seen that is similar, in many respects, to thepreviously described embodiment. As illustrated in FIG. 2, there isprovided a concrete base 216 including embedded therein a number ofanchor elements 218. Concrete base 216 may be poured in place andrequires minimal or nor excavation. In an exemplary configuration,concrete base 216 may be sixty feet in diameter and may be provided as ashallow foundation extending just below the frost line, perhaps two tothree feet in depth.

A second concrete base support 230 may be rectangular and centrallypositioned within an open space within the circular concrete base 216.Concrete base support 230 is large enough to provide support fortemporary tower 210 which may be held in position by one or more guywires 224, 226. It should be appreciated that while the presentconstruction permits removal of tower 210, such tower may, nevertheless,be retained for other purposes including providing support forconductive cables associated with the wind generator, for access to thecentral portion of the tower above transition piece 312 or for otherpurposes not directly related to the tower construction.

Referring now to FIG. 3, there is seen an enlarge perspective view ofthe top portion of temporary tower 310 illustrated in FIG. 2 with aprecast concrete transition piece 312 placed thereon. Transition piece312 may be raised into position using a crane or other suitablemechanisms and is placed on flat pads 320, 322, 324 secured to the topsof vertical sections of tower 310. Transition piece 312 simply sits inplace and is more securely positioned by placement of staves and othersecuring devices as will be explained more fully later.

Transition piece 312 is constructed with as a multifaceted precastconcrete construction to include a number of facets 332, 334, 336, wherethe number of facets is equal to the number of staves to be positionedabout the perimeter of the transition piece 312. It should further benoticed that an elliptical aperture 340 is provided through the centralportion of transition piece 312 and provides a passage way throughtransition piece 312. Elliptical aperture 340 provides for the removalof an elongated sealing plate as will be more fully described later.

With reference now to FIGS. 4 and 5, it will be seen that a number ofpairs of staves 420, 422 are positioned with a wider base portion 440resting on concrete base 416 and a narrower top portion 432 simplyleaning against a correspondingly sized facet 436 of transition piece412. Methods and apparatus for the manufacture of staves 420, 422 willbe discussed in detail below with reference to FIGS. 19-23. Base portion440 may be secure against radial and lateral movement by attachment toone or more anchor elements 418. FIG. 5 illustrates a top view takenfrom line 16-16 of FIG. 4 showing a completed skirted base structureincluding concrete base 516, plural pairs of staves 520, 522 positionedat top portions thereof in contact with facets of transition piece 512.Also illustrated is elliptical aperture 540 exposing portions oftemporary tower 510.

FIG. 6 illustrates a top perspective view of the precast transitionpiece 612 with all staves 620, 622 in place and banded around with acorrugated metal collar 652. Elliptical aperture 640 is also illustratedproviding a passageway through transition piece 612. A number ofadditional features of transition piece 612 are more clearly illustratedin FIG. 6 including a number of conduits 662, 664, 666, 668, the ends ofwhich may be seen exposed on the ends of staves 620, 622. Conduits 662,664, 666, 668 extend, in certain embodiments, through the length ofstaves 620, 622. In certain other embodiments, conduits 662, 664, 666,668 may extend only a certain way down the length of staves 620, 622 tothen turn and join with other conduits to form a U-shaped conduit fromthe top portion the individual stave to emerge as separate legs of theU-shape in the same or, possibly adjacent stave. In assembled form, theconduits provide a passage way for a metallic strand that may bethreaded through the conduits to provide strengthened assembly of thevarious tower components. As will be explained further later, themetallic strands may be extended through further conduits provided infurther tower portions to further assist in securing the towercomponents together.

Referring to FIG. 7, it will be noticed that the illustration issubstantially identical to that of FIG. 6 with the addition of ametallic plate 742 covering elliptical aperture 640 (FIG. 6). Metallicplate 742 may be constructed of steel and has provided on the topportion thereof a number of standoffs 744, 746, 748 that are provided assupport for a lifting plate to be described later. It should be noticedthat metallic plate 742 is constructed to have a length and a width suchthat the width is narrower than the longer length of the ellipticalaperture 640 yet the width is wider than the narrower width of theelliptical aperture 640. In this way, metallic plate 742 may be turnedso that it will pass through elliptical aperture 640 for removal as anoptional final portion of the tower erection process.

FIG. 8 illustrates a view similar to that of FIG. 7 and furtherillustrates a tower lifting plate 802. Positioned around the perimeterof lifting plate 802 are a number of pedestals 804, 806, 808. Pedestals804, 806, 808 generally correspond to portions of an I-beam and includea flat top surface configured to interface with end edge of a steelcylindrical tower portion and to lift the steel cylindrical towerportion in place using air pressure as will be described more fullylater. In conjunction with the object of lifting the steel cylindricaltower portion using air pressure, a sealing ring 810 is provided aroundthe outer perimeter of lifting plate 802 that functions in combinationwith the inner surface of one or more precast concrete tower sections toprovide a substantially air tight seal.

With reference to FIG. 9, there is illustrated a view similar to that ofFIG. 8 and further illustrating a first precast concrete tower section902 shown partially in phantom to better illustrate aspects of theinternal construction. As will be noticed from FIG. 9, there are anumber of conduits 904, 906, 908 provided within the wall of the precastconcrete tower section 902. Conduits 904, 906, 908 are positioned tocooperate with conduits 662, 664, 666, 668 incorporated into staves 620,622 (FIG. 6) and provide guides through which metallic threads may bepassed to assist in securing the various tower components together. Asmay be seen most clearly in FIG. 9, precast concrete tower portion 902is sized to fit over lifting plate 802 and is supported in place by anumber of corbels or support blocks 822, 824 integrally incorporatedinto transition piece 812 and radially extending from the perimeterthereof, as best seen in FIG. 8.

With reference now to FIG. 10 there is illustrated a first precastconcrete tower section 1002 sitting in place on top of transition piece1012. Coupling ducts 1030, 1032, 1034, 1036, 1038 are installed tocouple ducts within the staves 1020, 1022 and precast concrete towersection 1002 to provide passageways for securing metallic strands.Referring now to FIG. 11, it will be seen that following placement ofcoupling ducts 1030, 1032, 1034, 1036, 1038, the space enclosed bycorrugated metal band 1052 (FIG. 10) is filled with concrete 1102 andsurrounded by a number of circumferential clamps 1140, 1142, 1144, 1146configured to place the poured concrete filled corrugated metal band1052 in compression.

With reference now to FIG. 12, it will be seen that a number of precastconcrete cylindrical tower sections 1202, 1204, 1206 may be stacked oneupon another to extend the height of the tower. Each section may includeconduits as previously illustrated as conduits 904, 906, 908 in FIG. 9and shown in phantom in tower section 1206 of FIG. 12. It should beappreciated that while three precast concrete sections 1202, 1204, 1206are illustrated in FIG. 12, such number of sections is exemplary only.In practice the number of sections may generally vary from one to fourdepending on desire final height. It should also be noted that while thepresent disclosure is directed primarily to the provision of precastconcrete tower sections, such is not a limitation of the present subjectmatter in that these sections may be constructed of other materialsincluding steel.

After the desire number of precast concrete tower sections have beenstacked, a final cylindrical steel section 1208 is positioned within thestacked concrete sections and lowered so as to contact the pluralpedestals 804, 806, 808 secured to the upper surface of lifting plate802 (FIG. 8). Cylindrical steel section 1208 includes a ringed toothengagement mechanism (not separately illustrated) on the lower portionof cylindrical steel section 1208 so that when cylindrical steel section1208 is raised and later rotated the mechanism meshes with a lockingtooth mechanism installed on the top portion of the top concrete towersection.

Referring now to FIG. 13, it will be seen that a wind powered generator1300 may be mounted to the top of cylindrical steel section 1308 and thecombination raised to a final operating position by forcing compressedair into the space between the end of the lower most precast concretetower section 1306 and the lifting plate 1302. Those of ordinary skillin the art will appreciate that the normally required wind turbineblades associated with wind generator 1300 may be attached to thegenerator prior to raising the assembly. Such turbine blades are notpresently illustrated. FIG. 14 illustrates the assembled tower in itsfully extended position.

With reference now to FIG. 15 there is illustrated a cross section of aportion of a precast concrete base 1516 including ballast fill 1520,1522 and stave anchoring features 1530 in accordance with certainexemplary embodiments of the present technology. As illustrated in FIG.15, a feature of the present subject matter resides in the ability ofthe base support to be provided with minimal excavation requirements. Assuch, relatively shallow foundations placed just below the frost linefor the particular tower location. Generally this will be two to threefeet deep. This feature of being able to provide a poured I placecircular strip footing as illustrated in FIG. 2 may be extended to aprecast concrete sectionalized base as illustrated in FIG. 15. As shownin FIG. 15, base 1516 is provided with a flat lower portion 1540 andincludes a radially outward outer upstanding wall 1542 and includesintegral formed stave portions 1542. Integral stave portions 1542include anchoring features 1530 corresponding to the metallic strandreceiving conduits previously discussed with respect to FIG. 6 andconduits 662, 664, 666, 668. A plurality of sections corresponding tobase 1516 may be placed in a circular trench containing compactedmaterial 1550 which, in an exemplary configuration, may be one to sixfeet thick. Each of the plurality of sections may be secured together bymetallic threads threaded through integral conduits 1562, 1564 and theentire assembly may be provided with additional ballast 1520, 1522 inthe form of, for example, a stone fill. FIG. 16 illustrates an alternateconfiguration of the precast base structure that is identical in everyway to that of FIG. 15 except that upstanding wall section 1542 has beenreplaced with a separated corrugated metal structure 1642 and a seriesof post tensioning bands 1652 which function to retain ballast.

Referring now to FIG. 17, there is illustrated a multi-stage tower basegenerally 1700 designed to provide support, for example, for largercapacity turbines positioned at heights higher than single stage towersupports. As seen in FIG. 17, a top portion generally 1702 ofmulti-stage tower base 1700 is constructed in a manner similar to thatshown and described in conjunction with FIGS. 4 and 4. Thus, in FIG. 17it will be seen that a number of pairs of staves 1720, 1722 arepositioned with a wider base portion 1740 resting on concrete base 1716and a narrower top portion 1742 simply leaning against a correspondinglysized facet 1736 of transition piece 1712.

In a manner similar to that illustrated in FIG. 5, a completed topportion 1702 of skirted tower base 1700 includes concrete base 1716 andplural pairs of staves similar to staves 1720, 1722 positioned with topportions thereof in contact with other facets of transition piece 3712and bottom portions resting on concrete base 1716. In exemplaryconfigurations, concrete base portion 1716 may be either pre-cast orcast in place.

A lower portion generally 1704 of multi-stage tower base 1700 is similarto the top portion 1702 and supports concrete base 1716 by way of pluralpairs of staves exemplarily illustrated as staves 1744, 1746. A centralsupporting tower 1710 rests on concrete support 1752 and extends fromconcrete support 1752, through a central opening 1718 in concrete base1716, and upward to support transition piece 1712. As in previousembodiments, central tower 1710 may correspond to a temporary orpermanent structure.

In an exemplary embodiment, the upper portion 1702 of tower base 1700may incorporate about six pairs or twelve staves while lower portion1704 may incorporate nine or ten pairs or eighteen to twenty staves. Ofcourse, different numbers of staves may be incorporated in both theupper and lower portions of tower base 1700 depending on constructionrequirements for a particular embodiment, or depending on particulardesign criteria for given customers.

With reference now to FIG. 18, there is illustrated an exemplaryimplementation of “U” shaped tendons to provide multiple joint crossingand enhanced stave retention. The illustrated tower section correspondsto a number of staves 1822, 1824, 1826 configured to support a concretering generally 1828, which staves are secured together at least in partby a number of individual tendons 1810, 1812, 1814, 1816. The assemblyis designed to support a cylindrical steel tube section 3802 with theassistance of tube support structure 1804. An upper portion of steeltube 1802 (not shown) may be configured as well understood by those ofordinary skill in the art to support a wind turbine.

Staves 1822, 1824, 1826 abut each other at joints 1832, 1834, and areheld in place by tendons 1810, 1812, 1814, 1816. In accordance withpresent technology, tendons 1810, 1812, 1814, 1816 are configured topass through tubes cast into concrete ring 1828 and each of the staves1810, 1812, 1814, 1816 as “U” shaped formations crossing adjacent stavesat multiple locations generally designated along lines X, Y, and Z.

An exemplary tendon 1842 is secured at the top of concrete ring 1828 andpasses through tubes embedded in concrete ring 1828. Such exemplarytendon 1842 then passes through similar tubes embedded in stave 1822until it reaches a point 1844 where the tendon is divided into a firstportion that loops around to point 1854 and exits at point 1852 again atthe top of concrete ring 1828. A second portion of tendon 1842 continueson to point 1846 where it again is split, with one portion going topoint 1856 and a second portion going on to point 1848. The tendonportion advancing to point 1848 passes through tubes embedded in bothstaves 1822 and 1824, and then joins up with the remaining portions,including those that pass through tubes in both staves 1822 and 1824between points 1846 to 1856 and 1844 to 1854. Similar separating andrejoining of the several other tendons occurs with all of the individualstaves.

In accordance with present technology, such separating of the individualtendons into multiple portions provides for enhanced coupling of thestaves at multiple points along joints 1832, 1824. It should beappreciated that while present discussion describes tendons separatinginto three portions, each coupling adjacent staves at three separatepoints, the present subject matter is not so limited; therefore, thetendons may be separated into three, four or five or more portions, eachcrossing at separate points to secure plural staves.

Referring now to FIGS. 19-27, exemplary methodology and apparatus forthe manufacture of precast concrete structures used in the constructionof a base support will be described. In FIGS. 19-23, a concrete form maybe seen that is used to cast concrete precast staves, similar to staves420 and 422 illustrated in FIG. 4. The concrete form is used to castpre-stressed injection mold concrete staves in a manner that replicatesthe accuracy, precision, and finish of known match-casting techniques.Precast concrete staves molded using the techniques and apparatusdescribed herein have minimized defects in the surfaces of the stave,allowing for accurate matching with other structures used for example toconstruct the subject base support, including other staves or transitionpieces of the base support, such as transition piece 312 shown FIG. 3.In such manner, the various structural components of the base supportmay be secured together using adhesives as opposed to grouted jointtechniques.

It should be noted that the present methodologies may be practiced inconjunction with the fabrication of other concrete pieces involvingfabrication of structures where the advantages obtained for the concretepieces herein described are desired. Therefore, the presentmethodologies are not intended as being limited to production only ofthe concrete pieces herein disclosed or otherwise referenced.

With reference now to FIG. 19, a top plan view of an exemplary concreteform generally 1900 used to manufacture pre-stressed injection moldconcrete staves is illustrated. Arrows 1905 indicate locations foranchors for pre-stressing tendons placed in the concrete stave duringits formation. The concrete form 1900 forms an almost completelyenclosed cavity into which concrete is pumped from concrete feed yoke1910. Once the concrete form 1900 has been filled with concrete, thecasting cures and hardens inside the cavity formed by the concrete form1900 to form a concrete stave. Concrete form 1900 may also includevarious conduits 1907 or other structural components that are cast intothe stave. Methodology for casting such conduits or structuralcomponents into the stave will be discussed in more detail withreference to FIG. 24 and FIGS. 24A-24D.

As will be understood by those of ordinary skill in the art withoutadditional discussion, concrete feed yoke 1910 may be connected at oneend to a concrete supply source (not shown). The concrete supply sourcemay be configured to provide a supply of any type or mix of concretedesired for injection into concrete form 1900. For example, suchconcrete supply source may provide a supply of a self-consolidatingconcrete mix for injection into the concrete form 1900. As illustratedin FIG. 19, concrete feed yoke 1910 may for example include a Y-jointgenerally 1915 to split the flow of concrete to opposite ends of theconcrete form 1900. Concrete feed yoke 1910 injects concrete into theconcrete form 1900 at any of a plurality of concrete injection ports1912, 1914, 1916 and 1918 located in the concrete form 1900. The numberof ports may be varied as desired or needed, particularly to accommodatedifferent sized pieces being prepared per the present methodology and/orto accommodate variations in characteristics of the concrete beingpoured.

As indicated, the concrete feed yoke 1910 can be moved up and/or downthe concrete form 1900 to inject concrete into different areas of theconcrete form 1900. For example, once the area of the concrete form 1900corresponding to injection port 1912 has been filled, the concrete feedyoke 1910 may be moved “up” the concrete form 1900 and attached toinjection port 1914 to fill the area of the concrete form 1900associated with injection port 1914. It should be understood that in thepresent context the direction “up” preferably refers to that end or sideof the piece being poured which is relatively raised. Therefore, theports, in certain present embodiments, could be located in spacedplacements “moving” from side to side of the form 1900, rather than fromend to end thereof. It should also be understood that the differentareas of the concrete form are not separated by any physical separatoror divider, but rather combine together to form one continuous concreteform for molding of a concrete piece, in this example, a concrete stave.

Concrete form 1900 may also have ventilation ports 1975 to allow for theescape of air when the concrete form 1900 is being filled with concrete.Ventilation ports 1975 may be any type of vent for allowing the escapeof air, and may operate with or without vacuum assistance. After theconcreted form 1900 has been filled with concrete, the ventilation portmay be configured to be closed-off to provide a completely enclosedenvironment for curing of the concrete. In addition, using the teachingsprovided herein, those of ordinary skill in the art should appreciatethat the number and location of ventilation ports 1975 may varied asdesired or needed without deviating from the scope or spirit of thepresent technology.

With reference now to FIG. 20, a cross-sectional view of a concrete form2000 similar to the concrete form 1900 shown in FIG. 19 can be seen,with such cross-section taken along section line 20-20″ of such FIG. 19.As illustrated, concrete form generally 2000 includes two separablepieces, in this instance an upper form 2020 and a lower form 2030. Upperform 2020 and lower form 2030 combine together to form a substantiallyenclosed cavity into which concrete is injected in order to form casting2040. During the concrete injection process, upper form 2020 and lowerform 2030 are preferably secured together. One present methodology forsuch securement is to make use of a mechanical clamping mechanismgenerally 2025 such as, for example, a pin joint or a bolt joint.Importantly, upper form 2020 and lower form 2030 are adapted tocompletely cover, with the exception of injection ports and ventilationports 2075, the casting 2040 in the concrete form 2000.

Upper form 2020 and lower form 2030 may include structural reinforcingmembers so that the concrete form 2000 is self-supporting. In addition,upper form 2020 and lower form 2030 may include thermal insulationmaterials and/or electric heaters embedded in the bodies of the upperform 2020 and the lower form 2030, respectively. Such thermal insulationmaterials and/or embedded electric heaters are useful per presentsubject matter in assisting the concrete to cure and harden moreefficiently, and with less heat loss into the ambient air. The thermalinsulation materials and/or embedded heaters also reduce the amount ofPortland cement needed in the concrete, which reduces the emissions.Therefore, the present concrete pouring methodologies make moreefficient use of energy while also contributing less heat into thesurrounding environment, for two-fold improvement involvingenvironmental and energy concerns.

Referring still to FIG. 20, representative concrete feed yoke 2010injects concrete (as represented by the plurality of unlabeled arrows)into concrete form 2000 through respective cut-off valves 2060 providedin the concrete form 2000 at the plurality of concrete injection ports1912, 1914, 1916 and 1918. The cut-off valve 2060 may be a part of theconcrete form 2000 itself and may be adapted to provide a tight seal forthe concrete form 2000 when concrete is not being injected through thecut off valve 2060. As will be understood by those of ordinary skill inthe art, valves 2060 must be adapted so that they can open and closeeven after concrete has cured in the area adjacent the valve 2060. It isto be understood that the present methodologies are intended toencompass variations in the specific constructions of suchrepresentative valves 2060, or even the placement thereof relative to agiven feed yoke construction.

As illustrated, concrete form 2000 may also include vibrators generally2070. Vibrators 2070 may be used (if necessary for particular concretemixes and due to other factors), to assist concrete 2040 in filling thecavity formed by upper form 2020 and lower form 2030. For instance,vibrators 2070 may be particularly useful during troubleshootingscenarios when there is difficulty getting concrete to adequately flowinto the concrete form 2000.

In FIG. 20, representative concrete form 2000 rests on supports 2052 and2054 extending from floor or base 2050. The concrete form 2000, asillustrated, is resting so that the bottom surface 2032 of the lowerform 2030 is substantially parallel with the floor or base 2050.However, in particular embodiments, the height of support 2054 (or ofsupport 2052 and/or any other necessary supports) may be adjusted sothat concrete form 2000 is tilted about a transverse axis at an angle θso that the bottom surface 2032 of lower form is aligned along dashedline 2032′ of FIG. 20. The angle θ may be any angle in the range fromabout 0° when the bottom surface 2032 is substantially parallel to thefloor or base 2050 to about 90° when the bottom surface 2032 issubstantially perpendicular to the floor or base 2050. In certaininstances, it may be desirable for such angle to be greater than 90° ,such as to provide desired positioning of the form and/or workpiece forother processing considerations. As will be discussed below, the tiltingof the concrete form 2000 allows for the manufacture of concrete staves(or other pieces) with minimized defects in the surfaces of the stave(or other workpieces).

Referring now to FIG. 21, a side view of a concrete form generally 2100similar to those shown in FIGS. 19 and 20 can be seen. Concrete form2100 includes upper form 2120 and lower form 2130 that substantiallyenclose casting 2140. Concrete form 2100 is supported by supports 2152and 2152, which may be positioned and configured such that concrete form2100 is tilted about the longitudinal axis by an angle of Φ. In otherembodiments, the concrete form 2100 may be tilted by attaching a craneto the concrete form and lifting one end of the concrete form 2100 sothat the concrete form is tiled about the longitudinal axis by an angleof Φ. The angle Φ may be any angle in the range from about 0° when thebottom surface of the lower form 2130 is substantially parallel to thefloor or base 2150 to about 90° (or more) when the bottom surface of thelower form 2130 is substantially perpendicular to the floor or base2150. The only potential limit on the angle Φ is the maximum height Hthat can be attained for the concrete form 2100. As illustrated, as Φincreases from about 0° to about 90° , the height H of the concrete form2100 increase. There may exist certain limitations on the height H, suchas ceiling height of a manufacturing facility, that may coincidentallyserve as limits on the angle Φ, particularly where stave pieces may beon the order of 90 feet in length.

As illustrated in FIGS. 20 and 21, the concrete form of the presenttechnology may be tilted about a transverse axis, about a longitudinalaxis, or about both a transverse axis and a longitudinal axis, all inaccordance with the present subject matter. By injecting concrete“upwardly” into the tilted concrete form starting from the lowestelevation of the concrete form to the highest elevation, defects in thesurface of a casting molded in the concrete form may be minimized.

For example, referring to FIG. 19, if the concrete form 1900 was tiltedabout a longitudinal axis as shown in FIG. 21 so that the portion of theconcrete form 1900 corresponding to injection port 1918 was locatedabove the portion of the concrete form corresponding to injection port1912, concrete may first be injected at the bottom of concrete form 1900in the area corresponding to injection port 1912. Once the areacorresponding to injection port 1912 has been filled, the concrete feedyoke 1910 may be moved upward as indicated by the unlabeled arrows toinjection port 1914. Once the area corresponding to injection port 1914is filled, the concrete feed yoke 1910 may be moved even further upwardas indicated by the arrows to injection port 1916. Once the areacorresponding to injection port 1916 is filled, the concrete feed yoke1910 may be moved still even further upward as indicated by the arrowsto injection port 1918.

Utilizing such present technique, air pockets may be minimized in theresulting injected concrete, resulting in fewer defects on a surface orsurfaces of the casting. The defects may be even further minimized bycontrolling the pumping rate of the concrete into the concrete form. Byvarying the tilt angle of the concrete form about the longtinudinaland/or transverse axis, and by varying the pump rate of the concretefrom the concrete yoke, an optimal surface can be attained. All suchcombinations of variations are intended to be encompassed by the presentsubject matter.

As shown in FIG. 22, once concrete has been injected into the concreteform generally 2200 according to the methodology discussed herein, theconcrete form 2200 may be arranged substantially parallel with floor orbase 2250 for curing and hardening of the casting 2240. As illustrated,the supports 2252 and 2254 extending from or received on floor 2250 areconfigured such that the concrete form 2200 lies substantially parallelwith floor 2250. A concrete form 2200 may be moved from a tilted supportarrangement, such as those representatively shown in FIGS. 20 and FIG.21, to the substantially flat support arrangement of FIG. 22 through theuse of any appropriate transportation mechanism, including cranes. Thedetails of such lifting/transportation mechanisms are well known tothose of ordinary skill in the art and form no particular portion of thepresent subject matter.

As shown in FIG. 23, concrete form generally 2300 includes per thepresent subject matter two attachment mechanisms 2380 for securing theconcrete form to a crane or other device (not shown, or discussed indetail) for lifting the concrete form 2300. As discussed earlier, upperform 2320 and lower form 2330 may each include structural reinforcementso that the concrete form 2300 may be effectively and safely transportedby crane or the like from one area or location to another, such as in orabout a production facility.

With reference now to FIG. 24 and subfigures, FIGS. 24A-24D, anexemplary layout of a facility where the present technology may beutilized is illustrated. As shown, FIG. 24 splits the exemplary layoutof the facility into four quadrants. Quadrant “A” representssubstantially where the equipment and apparatus depicted in FIG. 24A arelocated. Quadrant “B” represents substantially where the equipment andapparatus depicted in FIG. 24B are located. Quadrant “C” representssubstantially where the equipment and apparatus depicted in FIG. 24C arelocated. Quadrant “D” represents substantially where the equipment andapparatus depicted in FIG. 24D are located.

With reference now to FIG. 24A, concrete is injected into concrete formsat casting table station generally 2410. As illustrated, casting tablestation 2410 includes two casting tables, casting table “A” and castingtable “B”. At casting table station 2410, concrete is injected intoconcrete forms similar to the manner discussed above with reference toFIGS. 19-21. Per present subject matter, the concrete form may be tiltedalong its longitudinal axis, its transverse axis, or both to minimizedefects in the surface or surfaces of the casting.

After the concrete form has been completely injected with concrete atcasting table station 2410, the concrete form may be moved, via crane asshown in FIG. 23 or by other form of transportation, to curing station2420. At curing station 2420, the concrete form may be positionedsubstantially parallel with the floor of the facility, similar to theconcrete form 2200 shown in FIG. 22. The concrete form remains at curingstation 2420 until the casting inside the concrete form has hardened andcured. A period of eight hours is one example of approximate time incuring station 2420 which may be practiced in various presentembodiments.

After the casting has cured inside the concrete form, the concrete formmay be transported to station 2430, which transportation is representedin both FIG. 24A and FIG. 24B. At station 2430, the upper form isremoved from the concrete form and the casting is removed. The castingmay be removed, for example, by a crane connected to chains threadedthrough conduits in the casting (refer to exemplary conduits 1907 inpresent FIG. 19). After the casting has been removed from the concreteform at station 2430, the casting may be stored at station 2440 until itis transported from the facility.

After the casting has been removed from concrete form, both the upperform portion and the lower form of the concrete form may be transportedto fabrication shop 2450 shown in FIG. 23C for repair, if necessary. Inthe alternative, the upper form and the lower form may be transported toconcrete form prep station 2460 shown in FIG. 24D.

At concrete form prep station 2460, both the lower form and the upperform are cleaned and prepared for casting. During such process, theupper form is inverted and held upside down. A crane or other device maybe used to invert the upper form. Once the upper form is inverted,various structural reinforcing members and conduits that are going to becast into the concrete stave are placed and secured in the upper form.After the various structural reinforcing members and conduits have beenplaced in the inverted upper form, the upper form and the lower form aretransferred to station 2470, where they wait to be used at casting tablestation 2410 shown in FIG. 24A.

Though not an aspect discussed in detail, each of FIGS. 24A through 24Dvariously illustrate railed carts which may be used for variously movingform and/or poured concrete pieces from station to station. The railedcarts may also be used to transport concrete or other concrete pumpingsystems from station to station. Details of such railed cart operationsor similar are well understood by those of ordinary skill in the art andform no particular aspect of the present subject matter.

Referring now to FIGS. 25-27, a concrete form may be seen that is usedto cast concrete precast ring structures for use in the base support.The concrete form is used to cast injection mold concrete ringstructures in a manner that replicates the accuracy, precision, andfinishes of known match-casting techniques. Precast concrete ringstructures molded using the techniques and apparatus described hereinhave minimized defects in the surface or surfaces of the ring structure,allowing for accurate matching with other structures used to constructthe base support, including other ring structures or transition piecesof the base support, such as transition piece 312 shown in FIG. 3. Insuch manner, the various structural components of the base support maybe secured together using adhesives as opposed to grouted jointtechniques.

With reference now to FIG. 25, an exemplary concrete form generally 2500used to manufacture injection mold concrete ring structures isillustrated. The concrete form 2500 forms an almost completely enclosedcavity into which concrete is pumped from concrete feed yoke 2510 toform casting 2540. As illustrated, concrete form 2500 includes an outerdiameter form 2520 and an inner diameter form 2530. Inner diameter form2530 includes a bottom surface 2532 upon which the bottom surface of thecasting 2540 rests. Once the concrete form 2500 has been filled withconcrete, the casting 2540 cures and hardens inside the cavity formed bythe concrete form 2500 to form a concrete ring structure. Concrete form2500 may also include various conduits or other structural componentsthat are cast into the ring structure, the details of which may vary inaccordance with the particular component or resulting structure underconsideration.

Concrete feed yoke generally 2510 may be connected at one end to aconcrete supply source 2550. The concrete supply source 2550 (not shown)may be configured to provide a supply of any type or mix of concrete asdesired or as needed in a particular instance for injection intoconcrete form 2500. For example, concrete supply source may provide asupply of a self-consolidating concrete mix for injection into theconcrete form 2600. As illustrated in FIG. 25, concrete feed yoke 2510may include a Y-joint to split the flow of concrete to opposite sides ofthe concrete form 2500. Concrete feed yoke 2510 injects concrete intothe concrete form 2500 through injection ports in the concrete form2500. The concrete form 2500 may have a plurality of injection portslocated throughout the height of the concrete form 2500, similar to theplurality of injection ports 1912, 1914, 1916, and 1918 discussed inconjunction with present FIG. 19.

As illustrated, concrete feed yoke 2510 injects concrete 2540 intoconcrete form 2500 through cut-off valves 2560 provided in the concreteform 2500 at the plurality of concrete injection ports. The cut-offvalve may be a part of the concrete form 2500 itself and may be adaptedto provide a tight seal for the concrete form 2500 when concrete is notbeing injected through the cut off valve 2560. The valve 2560 should beadapted so that it can open and close even after concrete has cured inthe area adjacent the valve 2560, as in the case with valves 2060discussed above in conjunction with present FIG. 20.

In accordance with the present subject matter and methodologies, theconcrete feed yoke 2510 may be adapted to inject concrete into theconcrete form 2500 from the lowest elevation of the concrete form 2500to the highest. For example, once the area corresponding to the lowestinjection port is filled, the concrete feed yoke 2510 may be movedfurther upward to an injection port at a higher elevation. By injectingconcrete into the tilted concrete form starting from the lowestelevation of the concrete form to the highest elevation, defects in thesurface of a casting molded in the concrete form generally 2500 may beminimized in accordance with the present subject matter.

Concrete form 2500 may also have ventilation ports 2575 to allow for theescape of air when the concrete form 2500 is being filled with concrete.Ventilation ports 2575 may be any type of vent for allowing the escapeof air, and may operate with or without vacuum assistance. After theconcreted form 2500 has been filled with concrete, the ventilation portmay be configured to be closed-off to provide a completely enclosedenvironment for curing of the concrete. In addition, using the teachingsprovided herein, those of ordinary skill in the art should appreciatethat the number and location of ventilation ports 2575 may varied asdesired or needed without deviating from the scope or spirit of thepresent technology.

Referring still to FIG. 25, it can be seen that similar to the concreteform for casting staves described in FIGS. 19-13, the concrete formgenerally 2500 may be tilted at a varying angle or angles θ about alongitudinal and/or transverse axis such that the bottom surface 2532 ofthe inner diameter form 2532 is aligned along dashed line 2532′ of FIG.25. The angle θ be any angle in the range from about 0° to about 90° (orabove in some circumstances).

Referring now to FIG. 26, the methodology and apparatus for strippingthe casting 2640 from concrete form 2600 will now be discussed indetail. First, outer diameter form 2620 is removed from the casting 2640such as with the assistance of jacks pushing up on jack supports 2610and such as with cranes pulling up on attachment elements 2680.

Due to the thermal expansion of the concrete form 2600 during the curingprocess of the casting 2640, it is helpful to create a temperaturegradient between the concrete form 2600 and the casting 2640 to assistin removal of the outer diameter form 2620 from the casting 2640. In oneembodiment, such temperature gradient is created by spraying steam orother high temperature water mixture generally 2692 onto the outerdiameter form 2620. In other embodiments, the thermal gradient may becreated using thermal insulation materials or embedded heaters in theouter diameter form 2620. After the outer diameter form 2620 has beensufficiently heated by the high temperature water mixture 2692, theouter diameter form 2620 may be more easily removed from the casting2640.

After the outer diameter form 2620 has been removed from the casting,the casting 2640 is removed from the inner diameter form 2630. Thecasting 2640 may be removed with the assistance of such as cranespulling up on the casting 2640 as well as with such as jacks pushing upon the bottom surface 2632 of the inner diameter form 2630 throughjacking ports. Jacking ports are illustrated in detail in FIGS. 27A.FIG. 27A provides a plan view of the bottom surface 2732 of an innerdiameter form having a plurality of jacking ports 2736. Further detailsof jacking ports 2736 are provided in FIGS. 27B and 27C.

Similar to the outer diameter form 2620, it is helpful to create atemperature gradient between the concrete form 2600 and the casting 2640to assist in removal of the inner diameter form 2630 from the casting2640. In the case of the inner diameter form 2630, however, it isdesirable to provide the opposite thermal gradient to that providedbetween the outer diameter form 2620 and the casting 2640. Accordingly,such temperature gradient is preferably created by spraying an ambienttemperature water mixture, water vapor, or air, generally 2694, onto theinner diameter form 2630. After the inner diameter form 2630 has beensufficiently cooled by the ambient temperature water mixture 2694, theinner diameter form 2630 may be more easily removed from the casting2640.

While the present subject matter has been described in detail withrespect to specific embodiments thereof, it will be appreciated thatthose skilled in the art, upon attaining an understanding of theforegoing, may readily produce alterations to, variations of, andequivalents to such embodiments, both as to present methodologies andapparatus. Accordingly, the scope of the present disclosure is by way ofexample rather than by way of limitation, and the subject disclosuredoes not preclude inclusion of such modifications, variations, and/oradditions to the present subject matter (either concerning apparatus ormethodology) as would be readily apparent to one of ordinary skill inthe art.

1-19. (canceled)
 20. A concrete form, comprising: a lower concrete form;and an upper concrete form secured to said lower form to define anenclosed casting volume within said concrete form; wherein said lowerand upper concrete forms collectively further define in said castingvolume at least one concrete injection port and at least one ventilationport, and provide said casting volume with a shape for forming therein aconcrete stave with a top portion and with a lower portion having agreater width than such top portion.
 21. A concrete form as in claim 20,further including anchors for securing pre-stressing tendons.
 22. Aconcrete form as in claim 20, wherein: said ventilation port isconfigured to be closed off; and said injection port includes a shut-offvalve.
 23. A concrete form as in claim 20, wherein said concrete formfurther includes a plurality of injection ports disposed along saidcasting volume; an embedded heater; and a vibrator.
 24. A concrete formas in claim 20, wherein said upper form and said lower form each includestructural reinforcing members to allow said concrete form to betransported by a crane or cart.
 25. A concrete form as in claim 24,wherein said concrete form further includes at least one attachmentmechanism for securing said concrete form to a crane or cart.
 26. Aconcrete form, comprising: an inner diameter form; and an outer diameterform received over said inner diameter form to define a casting volumewithin said concrete form; wherein said inner and outer diameter formscollectively further define in said casting volume at least oneinjection port and at least one ventilation port, and provide saidcasting volume with a shape for forming therein a concrete tubularstructure.
 27. A concrete form as in claim 26, further including anchorsfor securing post-tensioning ducts.
 28. A concrete form as in claim 26,wherein: said ventilation port is configured to be closed off; and saidinjection port includes a shut-off valve.
 29. A concrete form as inclaim 26, wherein said concrete form further includes a plurality ofinjection ports disposed along said casting volume; an embedded heater;and a vibrator.
 30. A concrete form as in claim 26, wherein said outerdiameter form and said inner form each include structural reinforcingmembers to allow said concrete form to be transported by a crane orcart.
 31. A concrete form as in claim 30, wherein: said concrete formfurther includes at least one attachment mechanism for securing saidconcrete form to a crane or cart; and said inner diameter form comprisesat least one jacking port.